The invention relates to a collision-protection device for vehicle passengers, comprising a gas cushion which is connected to a gas generator and is covered, in the folded-up state, by a cover flap, there being disposed on the gas cushion at least one escape opening for the controlled discharge of gas in the inflated state of the gas cushion.
Collision-protection devices of this type are known. For instance, German Patent Document DOS 19 35 426 describes a safety device housed in the steering mechanism of a vehicle and having a collapsed casing, wherein, during a collision, means for generating a flow of fluid cause the casing to expand into bearing contact against a part of the steering mechanism. In order to reduce the recoil of the driver when hitting against the casing, two blow-out mechanisms are provided in the base part of the casing. These are formed by essentially circular patches or sections which are fitted on the inner side of the casing and block off essentially circular openings. If there is a certain pressure present within the casing, the blow-out patches are torn away from the seam by which they are fastened to the base of the casing, thereby allowing fluid to flow out of the casing through the openings.
From German Patent 16 80 034, a further safety device for the protection of vehicle passengers is known, the bag of which, which is inflated in the event of an accident, exhibits a predetermined breaking point which is normally closed and is only burst open once a certain pressure obtaining in the bag has been exceeded. This predetermined breaking point comprises an opening in the bag, which opening is covered by a patch, the patch consisting of a weaker or thinner material than the bag.
In German Patent Document DE-GM 88 00 530, a collision-protection device for a vehicle passenger is described, the gas cushion of which is connected to a gas generator and exhibits four circular escape openings through which the filler gas blown into the gas cushion by the gas generator is able to escape. The escape openings are in this case obstructed by a closing part made from elastic, deformable material. A centrically disposed recess is disposed on this closing part, the cross-section of which recess is substantially smaller, in the rest state, than the cross-section of the escape opening of the gas cushion. This recess in the closing part changes its cross-section in dependence upon the internal pressure of the gas cushion, i.e. it automatically expands, in dependence upon the pressure situation, up to a maximum or then automatically diminishes again if the pressure should fall.
An object of the invention is to construct escape openings for gas cushions of collision-protection devices without additional closing parts or patches which have to be fitted to the gas cushion and seal off the escape opening or reduce its cross-section, the said escape openings allowing a controlled inflation of the gas cushion and a directed, areally distributed escape of gas from the gas cushion.
This object is achieved according to the invention by the fact that, in a collision-protection device for vehicle passengers of the above-mentioned type, the at least one escape opening points towards an open cover flap and is covered by this, at least when the gas cushion is inflated.
The cover flap situated in front of the escape opening acts as a valve for the escape opening, which valve effects a directed escape of gas from the inflated gas cushion whenever load is applied to it by a passenger. In particular, the open cover flap ensures an areally distributed escape of gas, thereby preventing body parts of the passenger from being directly caught in the flow. This helps to prevent hand and forearm injuries in the form of burns, since the gases, when escaping, have a high temperature. In a corresponding arrangement of the gas cushion in the folded state, the cover flap covers the escape opening throughout the inflation operation. It is not until the gas cushion is inflated that the cover flap, once a certain pressure in the gas cushion is exceeded, frees the escape opening to enable gas to be discharged.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.